An image forming apparatus includes a plurality of image forming units that are arranged in parallel so as to be opposed to an intermediate transfer belt or a transfer carriage belt. A black image forming unit that forms a black toner image is arranged at a downstream end or upstream end in the running direction of the intermediate transfer belt or the transfer carriage belt with respect to the other image forming units. The black image forming unit is configured so that its lubricant supplying unit contains a larger amount of lubricant.